[postgis-devel] RectDistance

[Paul Ramsey]

Hey all,
  I've had a branch running for a while, that Nik has tested a little,
for tree-based distance calculations. I've been doing some testing on
it and finding that when it's good, it's very very good (10x
improvements when dealing with large geometries) and when it's bad,
it's not so great (3x worse than existing naive distance on
small-vs-small geometries).
  All this so far without also reaching into the next obvious
enhancement, adding a caching behaviour, like the
point-in-polygon/geos code. That will make everything about 2x faster
yet, as about 50% of the time seems to be spent in building up trees.
  I'd like to merge my branch in, along with a temporary testing
function _ST_DistanceRectTree(geom, geom) so that we can figure out
how we exactly want to put this code to use. Any objections? If
nothing else, it will replace the current dead code lying in lwtree.c.

P.